Preparation and Characterization Study of Porous Silicon Doped with Cu and Ag

In this paper, porous silicon was prepared by using electrochemical etching technique of p-type silicon acceptor, with a resistivity of 1.5-4Ohm.cm, using hydrochloric acid with concentration of 24%. The etching current density effect 4, 12, 20mA/cm2 was carried out at constant etching time of 15min. The structural characteristics of the porous silicon and the doped porous silicon were studied and found an expansion in the spectrum of the X-rays and a simple shift in the diffraction angles while maintaining the surface direction (111). The morphological properties were studied using the atomic force microscope which showed pores formation and gives the pore diameter within the range of 19.08 to 44.73nm for the prepared samples. It was also noted that the rate of pore diameter and the thickness of the porous silicon layer increased with increasing etching current density. Electrical characteristics of the nanoscale porous silicon layer and the doped porous silicon with silver and copper showed that Current-Voltage (I-V) characteristics of the prepared samples to be a rectifying behavior. An improvement in the electrical characteristics of the doped porous silicon samples was observe

Exploring the environmental performance of liquid glass coating using Sol-Gel technology and responsive Venetian blinds in the tropics

The dynamic nature of tropical skies presents challenges for the built environment due to the momentous fluctuations and instability in solar irradiance and illuminance levels that cause limitations in responding to the needs of the indoor environment. The study aims to investigate the performance of daylighting strategies using liquid glass coating and responsive Venetian blinds in an office building in the tropics. The objective of this study is to systematically examine the impacts of proposed strategies on indoor environmental conditions. The study was experimentally investigated by utilising field measurements in full-scale cellular offices in a real environment and simulation using Radiance. The results indicated that responsive Venetian blinds provided steady daylight levels between 375 lx and 588 lx in the centre of the room, while a further integration with liquid glass coating provided a glare control with a maximum of 33.71% (Imperceptible) using Daylight Glare Probability. The indoor air temperature was reduced by 3.42 °C with liquid glass coating and 2.85 °C with responsive Venetian blinds. The outputs of assessing the performance of static and responsive strategies demonstrated new findings that are significant to developing these strategies in the tropics

A review of using IoT for energy efficient buildings and cities: a built environment perspective

Applications of the Internet of Things (IoT) are rapidly utilized in smart buildings and smart cities to reduce energy consumption. This advancement has caused a knowledge gap in applying IoT effectively by experts in the built environment to achieve energy efficiency. The study aims to provide an extensive review of IoT applications for energy savings in buildings and cities. This study contributes to the field of IoT by guiding and supporting built environment experts to utilize IoT technologies. This paper performed a thorough study using a systematic review that covered an overview of IoT concepts, models, applications, trends and challenges that can be encountered in the built environment. The findings indicated limitations in developing IoT strategies in buildings and cities by professionals in this field due to insufficient comprehension of technologies and their applied methods. Additionally, the study found an indefinite implementation and constraints on using IoT when integrated into the built environment. Finally, the study provides critical arguments and the next steps to effectively utilize IoT in terms of energy efficiency